heart disease

Are Our Healthy Years Getting Shorter?

by

What Does This Mean For You?

Author: Dr. Stephen Chaney

If you’ve ever traveled the subway system in London, you can’t have missed the “Mind the Gap” signs warning not to put your foot in the gap between the subway and the platform.

That warning is more important than ever in an age where people look at their cell phones rather than where they are walking. Of course, if they are looking at their cell phones, they might miss the sign and…

But today’s “Health Tip” is not about subway gaps. It’s about a far more important gap – the gap between our healthspan (how many years we enjoy good health) and our lifespan (how many years we live).

A recent study (L Gimeno et al, The Journals of Gerontology, Series B, 79(8), gbae113, 2024) suggesting that our healthy years are getting shorter caught my attention.

All of us imagine that our golden years will be ones of vibrant health. We’ll travel to exotic places. We’ll take long walks in the mountains. We’ll play with our grandchildren. Life will be wonderful.

But if this study is correct, none of that will happen for many young Americans. They will be too frail and sick to enjoy their golden years. They will be surviving rather than thriving.

So, in today’s “Health Tips From the Professor” I will review the study and tell you what it means for you.

How Was The Study Done?

clinical studyThe investigators used data on 114,526 adults >50 (average age = 63) from developed countries (the United States, England, and continental Europe). Specifically, they used data from people who participated in the Healthy and Retirement Study (26,939 people in the United States), the English Longitudinal Study on Ageing (14,992 people in England), and the Survey of Health, Ageing, and Retirement (72,595 people in continental Europe) between 2004 and 2018.

These surveys collected data on health-related outcomes every 2 years. The outcomes measured were:

  • Six activities of daily living (ADLs) such as eating, bathing, and walking.
  • Four instrumental activities of daily living (IADLs) related to essential tasks such as grocery shopping or preparing a hot meal.
  • Seven measures of mobility difficulties and motor coordination tasks such as walking one block, lifting 10 pounds, or picking up a small coin from a flat surface.

The assumption was that the severity of limitations was ADL > IADL > mobility difficulties. This is based on previous research showing that a person with ADL limitations is likely to have IADL limitations and mobility difficulties. And a person with IADL limitations is likely to have mobility difficulties. Based on this assumption, they classified participants in this study into 4 disability categories:

  • Mild disability: ≥1 IADL limitations and any number of mobility difficulties.
  • Moderate disability: 1-2 ADL limitations with any number of IADL limitations and mobility difficulties.
  • Severe disability: ≥3 ADL limitations with any number of IADL limitations and mobility difficulties.

The study also measured the prevalence (percent of the population) with:

  • Obesity
  • Heart disease.
  • Diabetes
  • Cancer
  • Lung disease.
  • High blood pressure.
  • High cholesterol.

Finally, the study also measured grip strength because loss of grip strength is considered an indicator of future disabilities.

The unique feature of this study is it compared the health and disability of people who were at the same age when tested but were born in different decades ranging from 1925 to 1955.

Because of the rapid change in diet and lifestyle following World War II, the health and disability of people born in the 1936-1945 decade encompassing World War II was used as the standard to which all other decades were compared.

Are Our Healthy Years Getting Shorter?

Some of you may have skipped over the previous section, so I will repeat the way these data were analyzed because it is crucial to your understanding of the study.

“The unique feature of this study is it compared the health and disability of people who were at the same age when tested but were born in different decades ranging from 1925 to 1955.

Because of the rapid change in diet and lifestyle following World War II, the health and disability of people born in the 1936-1945 decade encompassing World War II was used as the standard to which all other decades were compared.”

When looking at data from the United States, there were two distinct patterns.

The vertical line in the center of the graph represents the health and disability status of people born during World War II because all comparisons in this study were to people born in the decade encompassing World War II. A worsening of health and disabilities is indicated in red and an improvement in health and disabilities is shown in green. 

Pattern A was characteristic of a constant worsening of health and disabilities from people born in the decade starting in 1925 to people born in the decade starting in 1955.

This pattern was seen for:

  • Obesity
  • Heart disease.
  • Diabetes
  • Lung disease.
  • High blood pressure.
  • High cholesterol.
  • Severe disabilities.
  • Reduction in grip strength.

Remember, this study is measuring health and disability of people at the same age. The only difference is when they were born. It tells us people in their 50s, 60s, or 70s born in 1955 or later are in poorer health than people of the same age who were born in 1925.

And it’s not just the United States. For obesity and health parameters the pattern was the same for England and Europe. For severe disabilities the pattern was the same for England but was not as clear for Europe.

Two things should be noted for this pattern:

  • The worsening of health and the increase in severe disabilities comes despite the vast improvements in the health care systems in these countries and improved understanding of the causes of these diseases.
  • Obesity is likely a major driver of our declining health and increased disability. However, it is not the only driver. If the investigators had graphed the percentage of highly processed foods in the diet or the decline in regular exercise, the pattern would have been similar.

Pattern B shows an improvement in the period leading up to World War II and a deterioration in the period after World War II. The authors interpreted the improvement prior to World War II as due to improvements in health care and the deterioration after World War II as due to changes in diet and lifestyle.

This is the pattern seen for mild and moderate disabilities in the United States. The pattern for mild and moderate disabilities was not as clear for England and Europe.

The authors concluded, “In all regions, we found evidence for worsening health across cohorts [groups of people born in successive decades], particularly for those born after 1945.”

What Does This Study Mean For You?

QuestionsI don’t want to overinterpret this study. This study breaks new ground, but it has some limitations that I would characterize with three statements:

  • It is a very difficult study to do perfectly.
  • There are several factors that could affect the interpretation of the data and the outcome of the study.
  • The authors made a valiant effort to correct for any factors that could have affected the outcome.

For more details about the factors that might affect the outcome of the study and how the authors corrected for them, read the study.

However, this is the first study to use this approach to gauge the decrease in healthy years (healthspan) in developed countries over the past 40 years. It has its flaws, but it is consistent with several other studies documenting declining health in the current generation of young adults. For example, in a recent issue of “Health Tips From the Professor” I reviewed a study showing that colon cancer rates are increasing at an alarming rate for young adults in this country.

At the beginning of this article, I talked about the gap between our healthspan (how many years we enjoy good health) and our lifespan (how many years we live).

This study suggests that the onset of significant health issues and disabilities is occurring at a younger age today than for people born before World War II. In short, it suggests that our healthspan (the number of healthy years) is getting shorter.

This study did not look at lifespan, but numerous studies show that our lifespan is still increasing. So, the gap between healthspan and lifespan appears to be getting larger. In simple terms this means that when today’s young adults reach their “golden years”, they may spend more of those years in poor health than those of us born in the 1940’s.

But, what does this mean for you? The take home lesson should be, “This doesn’t have to be. You don’t have to be frail and sickly in your golden years. We know how to prevent this.”

  • It starts with a healthy diet – a whole food, primarily plant-based diet with lots of colorful fruits and vegetables, whole grains, nuts and seeds.
  • Add in a regular exercise program with a mixture of aerobic and resistance exercises.
  • Include an individualized supplement program.

You notice I didn’t list weight control as one of the top three prevention strategies. That’s because I don’t recommend fad diets and rapid weight loss programs. If you do the first three things well, your weight will come off naturally – a little bit at a time.

And once you have mastered all four things, you will increase your healthy years and narrow the gap between your healthspan and your lifespan. You can look forward to golden years filled with vitality and adventure.

The Bottom Line

A recent study used an innovative approach to quantify the deterioration in health and the physical ability to function well in daily activities as we age. The unique feature of this study is it compared the health and disability of people who were at the same age when tested but were born in different decades ranging from 1925 to 1955.

The study found a constant worsening of health and disabilities from people born in the decade starting in 1925 to people born in the decade starting in 1955 for:

  • Obesity
  • Heart disease.
  • Diabetes
  • Lung disease.
  • High blood pressure.
  • High cholesterol.
  • Severe disabilities.

The authors concluded, “We found evidence for worsening health across cohorts [groups of people born in successive decades], particularly for those born since 1945.”

In short, people born in recent years have fewer healthy years (a shorter healthspan) than people born before World War II. And since our lifespans are getting longer, this means the gap between our healthspan and our lifespan is increasing.

All of us imagine that our golden years will be ones of vibrant health. We’ll travel to exotic places. We’ll take long walks in the mountains. We’ll play with our grandchildren. Life will be wonderful.

But if this study is correct, none of that will happen for many of today’s young adults. They will be too frail and sick to enjoy their golden years.

For more details about this study and how you can increase your healthy years, narrow the gap between your healthspan and your lifespan, and look forward to golden years filled with vitality and adventure, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Is Olive Oil Overrated?

by

What Is The Truth About Olive Oil And You? 

Author: Dr. Stephen Chaney 

You may have seen headlines claiming that olive oil doesn’t deserve its “health halo”. It isn’t as healthy as many experts have claimed. It is overrated.

These headlines aren’t referring to the scandalous practice of selling “extra virgin” olive oil that contains cheaper oils. That is another topic for another day.

The headlines are claiming that, while the Mediterranean diet is healthy, it is fruits, vegetables, whole grains, legumes, and fish that make the Mediterranean diet healthy. Their claim is that olive oil has little to do with it.

To evaluate these claims I have reviewed the study (AK Krenek et al, Journal of the American Heart Association, Volume 13, Number 15:e035034, July 24, 2024) behind the headlines.

And to provide context, I have also reviewed another recent study (M Guasch-Ferre et al, Journal of the American College of Cardiology, Volume 79, Number 2, 2022).

How Were These Studies Done?

clinical studyThe two studies were very different:

The First Study used a randomized cross-over design to compare high and low olive oil diets.

In the randomized cross-over design participants were randomly assigned to one of the two diets at the beginning of the study. They followed that diet plan for 4 weeks. And after a one week “washout” they followed the other diet plan for 4 weeks. In this type of study each participant serves as their own control.

Study participants (50 obese participants, average age = 64, 75% women, 72% white, ≥ 5% risk of heart disease) were all eating a typical American diet.

Each of the experimental diets was a whole food plant-based diet, with comparable amounts of fruits, vegetables, whole grains, legumes, nuts, and seeds. Both diets were high in fiber, low in added sugar, and contained less than an ounce of animal products a day. In other words, the base diet was a healthy plant-based diet.

Participants in the high olive oil group were asked to add 4 tablespoons/day of extra virgin olive oil to their diet while participants in the low olive oil group were asked to restrict their olive oil intake to < 1 teaspoon/day.

No effort was made to control portion sizes or caloric intake. As we will see below, this was a major weakness of the study. As you might expect, fat intake was significantly greater for those on the high olive oil diet (49% of calories) compared to the low olive oil diet (32% of calories). Consequently, caloric intake was also significantly greater on the high olive oil diet.

All participants met with a dietitian/chef at the beginning of the study and were given access to online training programs and a dietitian hotline for questions. Dietary intake was measured by a 24-hour dietary recall 4-7 times prior to the study and 4 times during each diet period.

Fasting blood and urine samples were collected prior to the study and at the end of each 4-week diet period to measure biomarkers with possible predictive value for heart disease, such as LDL cholesterol.

The Second Study was a prospective cohort study using data obtained from 60,582 women in the Nurses Health Study and 31,801 men in the Health Professionals Follow-Up Study.

In a prospective cohort study a cohort or group of people (in this case, the 60,582 women and 31,801 men in the two studies) are followed over time (in this case for 28 years from1990 to 2018). The study then measures the association between some aspect of their diet and lifestyle (in this case the kind of fat in their diet) and health outcomes at the end of the study (in this case all-cause mortality, cardiovascular mortality, cancer mortality, neurodegenerative disease mortality, and respiratory disease mortality).

A strength of this study was that the diet of all participants was assessed every 4 years, which allowed the investigators to track changes in their diet over time. The intake of most fats was remarkably stable over the entire 28-year duration of the study.

However, as the bad news about margarine and the good news about olive oil entered the popular media, margarine consumption declined, and olive oil consumption increased. Because the investigators were able to track these changes over time, they were able to correct for them in their data analysis.

Is Olive Oil Overrated?

thumbs down symbolResults From The First Study: If we restrict ourselves to statistically significant observations, the results were as follows:

  • Switching from the baseline diet (typical American diet) to either the high olive oil or low olive oil diets for 4 weeks resulted in a significant decrease in total cholesterol, LDL cholesterol, HDL cholesterol, and blood glucose levels.
  • In this case, there was no statistically significant difference between the two diets.

However, when transitioning from the low olive oil diet to the high olive oil diet and from the high olive oil diet to the low olive oil diet, some statistically significant differences were observed.

For example, transitioning from the high olive oil diet to the low olive oil diet resulted in:

  • A 7% decrease in total cholesterol.
  • An 11% decrease in LDL-cholesterol.
  • A 2.2% decrease in HDL-cholesterol.
  • A 2% decrease in blood glucose levels.

And transitioning from the low olive oil diet to the high olive oil diet resulted in:

  • A 14% increase in total cholesterol.
  • A 14% increase in LDL-cholesterol.
  • A 15% increase in HDL-cholesterol.
  • A 17% decrease in blood glucose levels.

The authors of this study said, “Although both [whole food, primarily plant-based] diets improved [risk factors for heart disease], a low olive oil intervention may provide superior LDL-cholesterol lowering in individuals at highest risk [of heart disease]. Future studies are needed to determine if these short-term effects are sustainable and translate to improvements in cardiac outcomes…Nevertheless, a whole food primarily plant-based diet with relatively lower olive oil may be a useful tool for clinicians for improving cardiovascular risk compared with greater olive oil intake.”

The authors also went on to say, “…olive oil may not be the beneficial additive of a Mediterranean diet.”

thumbs upResults From The Second Study:

Higher intake of olive oil (>0.5 tablespoons/day compared to ≤1 teaspoon/day) resulted in:

  • A 19% decrease in the risk of all-cause mortality. And when that was broken down by cause it amounted to:
    • A 19% decrease in the risk of cardiovascular mortality.
    • A 17% decrease in the risk of cancer mortality.
    • A 29% decrease in the risk of neurodegenerative disease mortality.
    • An 18% decrease in the risk of respiratory disease mortality.

In a substitution analysis calculating the effect of consuming 10 g/day of olive oil instead of 10 g/day of:

  • Butter resulted in a 14% decrease in the risk of all-cause mortality.
  • Margarine or dairy fat resulted in a 13% decrease in the risk of all-cause mortality.
  • Mayonnaise resulted in a 9% decrease in the risk of all-cause mortality.
  • Other vegetable oils had no effect on all-cause mortality.
  • Results were similar when the investigators looked at the effect of replacing fats with olive oil on mortality due to cardiovascular disease, cancer, neurodegenerative disease, and respiratory disease.

The authors of the second study concluded, “Higher olive oil intake was associated with lower risk of total and cause-specific mortality. Replacing margarine, butter, mayonnaise, and dairy fat with olive oil was associated with lower risk of mortality.”

How can we reconcile these conflicting viewpoints? Let me start by looking at the flaws in the first study. Then I will summarize the “truth” about olive oil based on what these two studies tell us.

Is The Study Behind The Headlines Misleading?

flawsFirst let me summarize why I consider the study to be misleading. Then I will discuss why the headlines about the study are misleading.

Why The Study Is Misleading: The main conclusion of this study was that adding olive oil to a primarily plant-based diet increased the risk of heart disease. While this study is well-designed in some respects, it is flawed in others. I will summarize the flaws here:

Flaw Number 1: The authors rely on the relative effects of the high and low olive oil diets on LDL-cholesterol levels in predicting the effect of the two diets on heart disease risk. However, there is a major problem with this argument:

  • HDL-cholesterol levels move in the same direction. Both are decreased in the transition from the high olive oil to the low olive oil diet. Both are increased in the transition from the low olive oil to high olive oil diet. The ratio of HDL to LDL cholesterol changes very little, so it is almost impossible to predict what effect these changes will have on heart disease outcomes.

Flaw Number 2: This is related to the flaw I mentioned earlier. No effort was made to control portion size or caloric intake of participants on these diets. The high olive oil diet added 4 tablespoons of olive oil to the low olive oil diet. This significantly increased the fat and caloric intake of participants on the high olive oil diet.

  • Participants lost weight on both diets, but weight loss was significantly greater on the low olive oil diet. In their discussion, the authors admitted that the greater reduction in LDL-cholesterol on the low olive oil diet could have been due to the greater reduction in weight on that diet.

Flaw Number 3: I call this the “straw man” flaw. By adding 4 tablespoons of olive oil to the high olive oil diet the authors created the equivalent of a straw man that was easy knock over. Even if their conclusions were correct, nobody has recommended the addition of 4 tablespoons of olive oil to any diet as a heart-healthy approach.

Mediterraneans don’t add 4 tablespoons of olive oil to their diet. Olive oil is part of the foods they eat and the way they prepare their food.

Why The Headlines Are Misleading: Of course, the headlines were misleading because they ignored the many flaws of the study.

However, I find it amusing that some of the headlines came from “Forks Over Knives” an organization that advocates for a very low-fat plant-based diet. They were using this study to question the value of olive oil as part of a whole-food plant-based diet.

However, when you look at the study, 32% of calories came from fat in the low olive oil diet, and 49% of calories came from fat in the high olive oil diet.

For perspective:

  • The low-fat whole-food plant-based diet recommended by “Forks Over Knives” has <10-15% of calories from fat.
  • The Mediterranean diet typically contains 35-40% of calories from fat.
    • Around 18-19% of that is monounsaturated fat.
    • Around 8% of that is saturated fat.
  • The typical American diet also contains 35-40% of calories from fat.
    • Around 12-14% of that is monounsaturated fat.
    • Around 12% of that is saturated fat.

In other words, the low olive oil diet in this study resembles the fat content of the Mediterranean and typical American diets, not the low-fat whole food plant-based diet recommended by “Forks Over Knives”.

And the high olive oil diet contains fat levels not seen in any natural diet. Except for a few keto enthusiasts, I don’t know of any experts who think getting almost 50% of your calories from any kind of fat is a good thing.

What Is The Truth About Olive Oil And You?

The TruthAs described above, the study behind the headlines is a very small, very short study with multiple flaws. So, you can ignore headlines like “Olive oil is overrated” or “Olive oil doesn’t deserve its health halo.”

The second study I discussed is much larger (92,383 participants) and of much longer duration (28 years). More importantly, it measures health outcomes, not blood biomarkers that might predict health outcomes.

Finally, the second study was not measuring the health benefits of the Mediterranean diet, as many other studies have done. It was looking at the effect of varying olive oil intakes in the American diet. The high olive oil intakes in this study were less than those seen in the Mediterranean diet. This is good news for the average American who may feel overwhelmed trying to adopt to a Mediterranean diet.

This study reinforces previous studies showing that olive oil is healthy. But let me put this into context.

  • Olive oil is not a superfood. This study showed that it is no healthier than other plant oils. It is, however, considered one of the best vegetable oils for sauteing. It is also less susceptible to oxidation than seed oils, although I still recommend you store it in the refrigerator.
  • It is not something you add to your diet. It is something you incorporate into your diet. People who live in Mediterranean regions:
    • Cook with olive oil.
    • Use olive oil in their salad dressings and drizzle a little olive oil on cooked vegetable and pasta dishes instead of adding butter.
    • Dip their bread in olive oil rather than using butter or mayonnaise.
    • Use it in spreads like tapenade or hummus.
    • Use olives in cooking.
  • Finally, look for extra virgin olive oil. That doesn’t mean you need to spend “an arm and a leg”. But I would do a little online research before I bought the cheapest brand at the discount store.

The Bottom Line

You may have seen recent headlines claiming that olive oil is overrated and that it doesn’t deserve its “health halo”. So, I looked at the study behind the headlines.

It was a very small, very short study with multiple flaws. You can forget the headlines.

For context I also reviewed another recent study. It was a much larger (92,383 participants) and longer duration (28 years) study. More importantly, it measured actual health outcomes, not just blood biomarkers that might predict health outcomes.

It concluded that olive oil is good for us. It is healthier than most fats commonly found in the American diet, but it is no healthier than other plant oils.

For more details on these studies, what they mean for you, and how to incorporate more olive oil into your diet read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

 

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are All Plant-Based Diets Healthy?

by

Why Are Plant-Based Diets Healthy?

Author: Dr. Stephen Chaney

Unless you are like Rip van Winkle and have been asleep for the past 30 years, you have probably heard that plant-based diets are good for you. In fact, that advice is sound. It is based on multiple long-term studies.

But you may still be hesitant to make the switch. You are probably wondering if you have to be a vegan purist to benefit from a plant-based diet. If so, you are wondering whether you can make that drastic a change in your diet. Or, you may have already decided “that is a bridge too far” and don’t want to even consider it.

So, one important question is, “Do you have to go vegan to benefit from a plant-based diet?”

On the other hand, “Big Food, Inc” has made it easier than ever to switch to more “plant-based” eating. After all, sugar comes from plants. And highly processed grains come from plants. Add a few chemicals and you can come up with an endless supply of highly processed plant-based foods.

So, another important question is, “Can a diet of highly processed plant-based foods be as healthy as a diet of whole, unprocessed plant-foods?”

The study (Y. Wang et al., Nutrition Journal, 22: 46, 2023) I am reviewing today was designed to answer these two questions. It also represents the first meta-analysis to combine data from studies on the effects of plant-based diets on diabetes, heart disease, cancer, and mortality into a single study.

How Was The Study Done?

clinical studyThe investigators performed a meta-analysis of 76 studies with 2,230,443 participants that looked at the associations of plant-based dietary patterns and the incidence of type 2 diabetes, cardiovascular disease, cancer, and mortality among adults 18 years or older.

The characteristics of study participants ranged from:

  • 25 to 87 years old.
  • BMI of 20 to 30.

And the duration of the studies within the meta-analysis ranged from 2 to 36 years.

The adherence to plant-based diets was defined as higher consumption of plant-based foods and lower consumption or exclusion of animal-based foods.

The meta-analysis also included studies looking at the effect of changing from a more animal-based to a more plant-based dietary pattern.

The meta-analysis included studies looking at the benefit of vegan and vegetarian diets. In terms of participants these studies represented just over 50% of the data in the meta-analysis. So, this meta-analysis was ideally positioned to determine whether vegan and vegetarian diets were more beneficial than other primarily plant-based dietary patterns that included some animal foods.

The methodology used to classify diets as primarily plant-based varied from study to study. But in each case the study participants were divided into quartiles ranging from consuming the most plant-based diet to consuming the least plant-based diet.

The study then compared study participants with the highest adherence to plant-based diets to those with the lowest adherence to plant-based diets with respect to type 2 diabetes, cardiovascular disease, cancer, and mortality.

Finally, the study also compared adherence to healthy plant-based dietary patterns (whole or minimally processed fruits, vegetables, whole grains, beans, nuts, and seeds) to unhealthy plant-based dietary patterns (foods and drinks with added sugar, highly processed plant foods, and starchy vegetables).

Are Plant-Based Diets Healthy?

When comparing highest to lowest adherence to plant-based dietary patterns the risk of:

  • Type-2 diabetes was reduced by 18%.
  • Cardiovascular disease was reduced by 10%.
  • Cancer was reduced by 12%.
  • Mortality was reduced by 16%.

In short, all the news was good for primarily plant-based dietary patterns.

Are All Plant-Based Diets Healthy?

Increased adherence to a healthy plant-based dietary pattern (That term is defined in the methods section above) was associated with an even better reduction in disease risk. For example:

  • Type-2 diabetes was reduced by 21%.
  • Cardiovascular disease was reduced by 15%.
  • Cancer was reduced by 13%.
  • Mortality was reduced by 14%, which was statistically indistinguishable from the reduction in mortality associated with all plant-based dietary patterns above.

Factory FarmIn contrast, increased adherence to an unhealthy plant-based dietary pattern was associated with increased risks of disease. For example:

  • The risk of type 2 diabetes increased by 8%.
  • The risk of cardiovascular disease increased by 14%.
  • The risk of cancer increased by 7%.
  • The risk of mortality increased by 16%.

In short, plant-based dietary patterns consisting of whole or minimally processed plant foods are good for you. Plant-based dietary patterns consisting of highly processed plant foods are not.

Are Vegan and Vegetarian Diets More Beneficial Than Other Plant-Based Dietary Patterns?

Mediterranean Diet FoodsTwenty seven of the studies within this meta-analysis compared vegetarian or vegan dietary patterns with animal-based dietary patterns. These studies had 1,343,967 participants, which amounts to 57% of the participants in the meta-analysis.

Thus, this meta-analysis was well positioned to determine relative benefits of vegan and vegetarian diets compared to other primarily plant-based dietary patterns that include some animal foods. The investigators reported that:

  • The risk reduction for type 2 diabetes was greater in studies with vegan and vegetarian diets than in studies with other primarily plant-based diets.
  • No other statistically significant benefits were observed for vegan and vegetarian diets compared to other primarily plant-based diets.

In short, you don’t need to become a vegan to experience the health benefits of a plant-based diet.

In contrast, increased adherence to an unhealthy plant-based dietary pattern was associated with increased risks of disease. For example:

  • The risk of type 2 diabetes increased by 8%.
  • The risk of cardiovascular disease increased by 14%.
  • The risk of cancer increased by 7%.
  • The risk of mortality increased by 16%.

In short, plant-based dietary patterns consisting of whole or minimally processed plant foods are good for you. Plant-based dietary patterns consisting of highly processed plant foods are not.

What If You Change From An Animal-Based To A Plant-Based Diet?

Food ChoicesIf you have been consuming an animal-based diet for years, you may be wondering whether it is too late to change. Has the damage already been done?

Six studies within this meta-analysis examined the effect of changing from an animal-based diet to a plant-based diet on type 2 diabetes and mortality. Changing to a more plant-based dietary pattern:

  • Reduced diabetes by 17% and mortality by 5%.

In short, it’s never too late to switch to a more plant-based dietary pattern.

Why Are Plant-Based Diets Healthy?

The short answer is that we don’t know for sure, but the authors mentioned several popular hypotheses.

  • Obesity is a risk factor for type 2 diabetes, cardiovascular disease, and certain types of cancer. And studies have shown that people consuming plant-based diets tend to weigh less.
  • The increased fiber content and higher ratio of polyunsaturated fats to saturated fats lower cholesterol levels and improve blood lipid profiles, which are associated with a lower risk of cardiovascular disease.
  • Plant-based diets are anti-inflammatory, which reduces the risk of all three diseases.
  • Plant foods are rich in polyphenols and other phytonutrients that are associated with reduced risk of cardiovascular disease, lower blood pressure, and improvements in insulin sensitivity.
  • Plant foods are metabolized by gut bacteria to metabolites that are associated with reduced risk of type 2 diabetes and cardiovascular disease.
  • Plant foods support healthy gut bacteria associated with a reduced risk of several diseases.
  • Finally, plant-based dietary patterns are associated with no or reduced consumption of red and processed meats, which increase the risk of type 2 diabetes, cardiovascular disease, and certain types of cancer.

For a more detailed discussion read the article).

What Does This Study Mean For You?

The authors of this study concluded, “Higher adherence to plant-based dietary patterns, especially from healthy sources, may be universally beneficial for the primary prevention of type 2 diabetes, cardiovascular disease, cancer, and mortality. The current study provides further evidence in support of current recommendations that emphasize consuming high-quality plant-based foods for achieving optimal health.”

“Future studies are needed to elucidate…mechanistic pathways linking plant-based diets with multiple disease outcomes.”

I would just like to emphasize a few points:

  • These are all association studies. It takes decades for diseases like diabetes, heart disease, and cancer to develop. So, it is impossible to confirm these findings with double blind, placebo-controlled studies. However, when you have 76 studies with over 2 million participants all pointing to the same conclusion, it is hard to ignore the findings.
  • The good news is that you don’t have to become a vegan to experience these benefits. There are many healthy primarily plant-based diets available. Choose the one that best fits your food preferences and lifestyle.
  • Be aware that whatever diet you choose, Big Food Inc is only too happy to provide you with highly processed foods that fit that dietary pattern. Don’t fall for that trap. Stick with whole or minimally processed plant foods.
  • If your current diet isn’t the best, it is never too late to switch to a healthier primarily plant-based diet.

The Bottom Line

A recent meta-analysis of 76 studies with 2,230,443 participants looked at the associations of plant-based dietary patterns and the incidence of type 2 diabetes, cardiovascular disease, cancer, and mortality among adults 18 years or older.

The authors of the study concluded, “Higher adherence to plant-based dietary patterns, especially from healthy sources, may be universally beneficial for the primary prevention of type 2 diabetes, cardiovascular disease, cancer, and mortality. The current study provides further evidence in support of current recommendations that emphasize consuminh high-quality plant-based foods for achieving optimal health.”

Other key points from the study are:

  • These are all association studies. It takes decades for diseases like diabetes, heart disease, and cancer to develop. So, it is impossible to confirm these findings with double blind, placebo-controlled studies. However, when you have 76 studies with over 2 million participants all pointing to the same conclusion, it is hard to ignore the findings.
  • The good news is that you don’t have to become a vegan to experience these benefits. There are many healthy primarily plant-based diets available. Choose the one that best fits your food preferences and lifestyle.
  • Be aware that whatever diet you choose, Big Food Inc is only too happy to provide you with highly processed foods that fit that dietary pattern. Don’t fall for that trap. Stick with whole or minimally processed plant foods.
  • If your current diet isn’t the best, it is never too late to switch to a healthier primarily plant-based diet.

For more details about how the authors came to these conclusions and what they mean for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 ______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are Calcium Supplements Safe?

by

What Does This Study Mean For You?

Author: Dr. Stephen Chaney 

Pendulum
Pendulum

Should you avoid calcium supplements because they increase your risk of heart disease? Some headlines and blog posts would have you believe that. You may have been told that by your doctor. But is it true?

Unfortunately, this is another example of the swinging pendulum that we often see in supplement studies. One day a study comes out saying that calcium supplements increase the risk of heart disease. A few months later another study comes out saying that is not true. Calcium supplements don’t increase heart disease risk.

The pendulum keeps swinging until you are totally confused. You don’t know what to believe. And “experts” (including your doctor) pick one side or the other depending on what they believe about supplements in general.

I have told you before that good scientists wait until multiple studies have been done and base their opinion based on what the preponderance of studies show. I can tell you that multiple studies have been done and the preponderance of studies show that calcium supplements do not increase the risk of heart disease. But that doesn’t prove that calcium supplements are safe. It just shows they are likely to be safe.

That is why the authors of the current study (X Huo et al, Current Developments In Nutrition, volume 7, Issue 3: 100046, March 2023) analyzed the weaknesses of previous studies and tried to design a study that lacked those weaknesses.

How Was This Study Done?

clinical studyThe investigators searched through the literature to identify all placebo-controlled, randomized clinical trials (the gold standard for clinical studies) assessing the effects of calcium supplements alone or calcium supplements with vitamin D on heart disease, stroke, and all-cause mortality.

They restricted their analysis to studies with at least 500 participants that lasted for at least a year. They further restricted their analysis to studies whose authors were willing to share unpublished data on the number of participants in each treatment group who had a heart attack, stroke, or any other kind of heart disease; died from heart disease; or died from all causes during the study.

They ended up with 11 clinical studies in their analysis. The breakdown was as follows:

  • Seven studies with 8,634 participants compared calcium alone with placebo.
    • Participants in these studies averaged 71 years old and were 79% female.
    • The daily calcium dose varied from 1.0 to 1.5 g/day.
    • The mean duration of treatment was 4.1 years (range = 2-5 years).
  • Six studies with 46,804 participants compared calcium plus vitamin D with placebo.
    • Participants in these studies averaged 65 years old and were 98% female.
    • The daily calcium dose varied from 1.0 to 1.5 g/day and the daily vitamin D dose ranged from 400 to 2,000 IU/d.
    • The mean duration of treatment was 6 years (range = 1.5-7 years).
  • In case you were wondering about the math, some studies included both calcium alone versus placebo and calcium plus vitamin D versus placebo.

The authors then combined the data from all 11 studies and performed a meta-analysis on the effect of calcium alone on adverse heart outcomes and calcium plus vitamin D on adverse heart outcomes.

Are Calcium Supplements Safe? 

calcium supplementsThe results were clear-cut.

  • Calcium alone was not significantly associated with any increased risk of heart attack, stroke, heart disease of any kind, deaths from heart disease, and deaths from all causes.
  • Calcium with vitamin D was not significantly associated with any excess risk of heart attack, stroke, heart disease, deaths from heart disease, and deaths from all causes.

In their discussion, the authors pointed out two caveats to their conclusions:

  • In the calcium only portion of the meta-analysis the number of participants who experienced a stroke or types of heart disease other than heart attack and stroke was very small. So, they could not exclude an absolute increased risk of 0.3-0.5% per year for these types of rare events.
  • The participants in the 11 studies included in their meta-analysis were not selected based on their risk of heart disease. So, the authors could not exclude the possibility that calcium supplements might increase the risk of heart disease in people who were already at high risk of heart disease.

The authors concluded, “This meta-analysis demonstrated that calcium supplements were not associated with any significant hazard for heart disease, stroke, or all-cause mortality…Hence, for people with low bone density and low absolute risks of heart disease, the present report demonstrates no concern about excess heart disease risks associated with calcium supplements.

However, further large trials are needed to assess the efficacy and safety of combined supplementation with calcium and vitamin D for the prevention of osteoporotic fracture in older people at high risk of heart disease.”

What Does This Study Mean For You?

Questioning WomanAs I said above, the preponderance of evidence suggests that calcium supplementation does not increase your risk of heart disease. This study reinforces that conclusion.

I can’t guarantee that some future study won’t come to the opposite conclusion, and the pendulum will swing again. And I can’t guarantee that your doctor has kept up with the most recent literature on calcium supplementation and heart disease risk.

The authors of this study also pointed out that we don’t have any clinical studies on the effect of calcium on heart disease risk if you are already at high risk of heart disease. So, if you are at high risk of heart disease, any advice that I or your doctor give you about calcium supplementation might be wrong. We simply don’t know.

Finally, I realize that you may be equally confused about whether calcium supplementation can strengthen your bones and reduce your risk of osteoporosis. I won’t discuss that question today. Instead, I will refer you to two previous articles I have written in “Health Tips From the Professor” on that topic.

The first article discusses the flaws in previous studies claiming that calcium supplements are ineffective at increasing bone density and preventing osteoporotic fracture.

The second article describes a bone-healthy lifestyle.

The Bottom Line

While the preponderance of studies have shown that calcium supplementation does not increase the risk of heart disease, that conclusion remains controversial.

To clarify that issue, a group of investigators searched through the literature to identify all placebo-controlled, randomized clinical trials (the gold standard for clinical studies) assessing the effects of calcium supplements alone or calcium supplements with vitamin D on heart disease, stroke, and all-cause mortality. They then performed a meta-analysis of those clinical studies.

Their meta-analysis showed that:

  • Calcium alone was not significantly associated with any increased risk of heart attack, stroke, heart disease of any kind, deaths from heart disease, and deaths from all causes.
  • Calcium with vitamin D was not significantly associated with any excess risk of heart attack, stroke, heart disease, deaths from heart disease, and deaths from all causes.

This study strengthens the conclusion that calcium supplementation does not increase the risk of heart disease.

For more details about the study and references discussing the effect of calcium supplementation on bone density, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

About The Author

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are Omega-3 Supplements Safe?

by

The Flaws And Blind Spots In This Study

Author: Dr. Stephen Chaney

Pendulum
Pendulum

Has the omega-3 pendulum swung again? The recent headlines are downright scary. For example:

  • “Fish Oil May Increase the Risk of Stroke and Heart Conditions.”
  • “Fish Oil Supplements May Cause Harm, Study Finds. Is It Time to Ditch Them?”
  • “Fish Oil Supplements May Lead to Heart Problems”.
  • “Regular Use of Fish Oil Supplements Might Increase, Rather Than Lessen, The Risk of First Time Heart Disease and Stroke Among Those in Good Cardiovascular Health.”

Yikes! That sounds bad. Should we be thinking about giving up our omega-3 supplements?

But wait. Just a few weeks earlier we were reading headlines about the benefits and lack of side effects from omega-3 supplements. That’s confusing. Which headlines are correct?

To answer these questions:

  • I will point out the flaws and blind spots in the study.
  • I will strip away the hyperbole and put the headlines into perspective.

How Was The Study Done?

clinical studyThe investigators made use of data from the UK Biobank Study. The UK Biobank Study is a large, long-term study in the United Kingdom which was designed to investigate the contributions of genetic predisposition and environmental exposure [including diet and supplementation] to the development of disease.

The UK Biobank Study enrolled 502,461 participants, aged 40-69 years, between January 1st, 2006 and December 31st, 2010. Participants were followed from entry into the program until March 31st 2021, an average of 11.9 years.

The current study excluded any participants who had a diagnosis of atrial fibrillation, heart failure, heart attack, stroke, or cancer at entry into the study, leaving 415,737 participants.

The participants were:

  • 55% women.
  • Average age of 56 years, with 83.4% of them below 65 years old at entry into the study.
  • 94.5% white.

The study was designed in a unique manner, in that it was designed to test the effect of omega-3 supplements on 6 specific transitions:

  • Primary prevention. This measured the transition of healthy (no diagnosed heart disease) people to either atrial fibrillation, major cardiovascular events, or death.
  • Secondary prevention. This measured the transition from atrial fibrillation to either major cardiovascular events or death.
  • Tertiary prevention. This measured the transition from major cardiovascular events to death.
  • Major cardiovascular events were further broken down to heart attacks, stroke and heart failure.

Participants were asked whether they used fish oil supplements when they entered the study and were categorized as either regular users or non-users. [Note: The users were not asked the dose or brand of fish oil supplements they used.]

Deaths were obtained from the national death registry and disease diagnosis from the National Health Service.

Are Omega-3 Supplements Safe?

omega-3 fish oil supplementHere is what the study found.

Primary Prevention – For healthy individuals (defined as having no diagnosed heart disease) using omega-3 supplements for an average of 11.9 years:

  • Increased the risk of atrial fibrillation by 13%.
  • Did not affect the risk of major cardiovascular events and death were unaffected by omega-3 supplementation.
  • When major cardiovascular events were broken down to their component parts, omega-3 supplementation:
    • Decreased the risk of heart failure by 8%.
    • Increased the risk of stroke by 5% (this was just barely statistically significance).
    • Did not affect the risk of heart attack.

Secondary Prevention – For individuals with atrial fibrillation omega-3 supplementation:

  • Decreased the risk of major cardiovascular events by 9%.
  • Decreased the risk of death by 8%.
  • When major cardiovascular events were broken down into their component parts, omega-3 supplementation:
  • Decreased the risk of heart attacks by 15%.
  • Had no effect on the risk of stroke or heart failure.

Tertiary Prevention – For people who suffered major cardiovascular events during the study omega-3 thumbs upsupplementation:

  • Decreased the risk of death by 8%.

Since this is a very complex set of data, I have coded positive results in green and negative results in red.

And as if these complexities were not enough, when the investigators broke these effects down by population groups:

  • Omega-3 supplementation decreased the transition from healthy to death for men (7% decrease) and participants older than 65 (9% decrease).

I will discuss the significance of these observations below.

The authors concluded, “Regular use of fish oil supplements might be a risk factor for atrial fibrillation and stroke among the general population but could be beneficial for [reducing] progression of cardiovascular disease from atrial fibrillation to major adverse cardiovascular events, and from atrial fibrillation to death.”

In short, they were suggesting that omega-3 supplements should be avoided by the general population because they have no positive benefits and might increase the risk of atrial fibrillation and stroke. But omega-3 supplements may be useful for those who already have heart disease.

Some of the articles you may have read about the study repeated this message. Others just emphasized the negative aspects of the study.

But is this message accurate? Let me start by discussing the flaws, blind spots, and hidden data in this study. Then I will summarize the 3 key findings of the study and tell you what they mean for you.

The Flaws, Blind Spots, And Hidden Data In This Study

flawsFlaws: As I said above, there were two major flaws in the study.

Flaw #1: The study did not identify the dose of supplement used. This is important because the increased risk of atrial fibrillation and stroke is primarily seen in clinical trials using high dose omega-3 supplements.

Flaw #2: This was an association study which cannot prove cause and effect. However, the authors of this study reported it as showing that omega-3 supplement use caused atrial fibrillation and stroke – and all the news reports on the study have repeated that claim.

Flaw #3: Other experts have pointed out that the authors inflated the risks associated with omega-3 supplementation by reporting relative risk rather than absolute risk. Let me try to simplify the distinction.

The risk of atrial fibrillation was 4.24% in the non-supplement users and 4.80% in the omega-3 supplement users. That is an absolute increase in risk of 0.56% (4.80% – 4.24%). This is the increase in risk you actually experience. In contrast, 4.80% is 13% greater than 4.24%, which is how relative risk is calculated.

In response to the questions you are probably thinking:

  • Yes, this is a perfect example of the Mark Twain quote, “There are lies. There are damn lies. And then there are statistics.”
  • Yes, all the percentages reported in this study are based on relative risk and are, therefore, inflated. However, I do not have access to their data, so I cannot tell you the absolute risk associated with their other observations.

Blind Spots: In their paper the investigators recommended against the use of omega-3 supplements to prevent heart disease because their data showed:

  • No benefit of omega-3 supplementation for preventing major cardiovascular events and deaths in a healthy population.
  • But did suggest an increased risk of atrial fibrillation and stroke in that same population.

However, their blind spot was in underestimating the difficulty of showing the benefit of any intervention in a healthy population. The example I always use is statin drugs. Statin Drugs:

  • Dramatically reduce the risk of a second heart attack and/or death in people who have already had a heart attack.
  • Reduce the risk of heart attacks in people who are at high risk of heart attacks.
  • Cannot be shown to reduce the risk of heart attacks in a healthy population.

This study suggests that omega-3 supplements are no different. In this study, omega-3 supplements:

  • Reduced the risk of death in people who had already experienced a major cardiovascular event like a heart attack or stroke.
  • Reduced the risk of major cardiovascular events and death in people with atrial fibrillation, which puts them at high risk for a heart attack or stroke.
  • Could not be shown to reduce the risk of major cardiovascular events or deaths in a healthy population.

Hidden Data: There are some important data that were buried in the text and supplemental figures but were Skepticignored in the concluding remarks of this study and all the articles written about it. For example:

  • The original study and all articles written about the study reported that omega-3 supplementation increased the risk of stroke in otherwise healthy individuals but ignored the observation that omega-3 supplementation decreased the risk of heart failure in that same group.

The second example of hidden data likely represents another blind spot of the authors. They concluded that omega-3 supplementation had no benefit for healthy individuals without asking whether omega-3 supplements might benefit higher-risk subpopulations within this group. To help you understand this statement let me start by giving you some perspective.

As I said above, statin drugs cannot be shown to reduce the risk of heart attacks in a healthy population. But when you include people at high risk of heart disease with healthy people in the dataset, you start to see a reduced risk of heart attacks.

Similarly, with supplements you often see no benefits with the general population, which is what is usually reported in the media. But when you look at higher risk groups within that population, the benefits of supplementation emerge.

This study is no different:

  • For healthy individuals, omega-3 supplementation had no effect on deaths during the 12-year follow-up period.
  • However, omega-3 supplementation reduced the risk of death by 9% for both men and people ≥ 65. These represent two groups with elevated risk of heart disease within the otherwise healthy population.
  • Once again, these data were completely ignored.

What Does This Study Mean For You?

This study made 3 major points:

Point #1: Let me start with the one you’ve heard the most about. The risk of atrial fibrillation and stroke associated with omega-3 supplementation is real. We should not ignore it.

But what this study and most of the reports on the study didn’t tell you is that the risk is dose dependent. The risk is primarily seen with high doses of omega-3s. While no one has done a comprehensive dose response analysis, I can tell you that these side effects are:

  • Seldom reported in clinical studies at doses of 1 gm/day or less.
  • Sometimes reported in clinical studies at doses of ≥2 gm/day.
  • Frequently reported in clinical studies at doses of ≥4 gm/day.

However, atrial fibrillation and stroke occur in a very small percentage of omega-3 users, even at 4 gm/day. At this point we have no idea why some people are susceptible to these side effects and others are not. More research in this area is clearly needed.

Until we know more about who is at risk, my recommendation for people who are trying to reduce the risk of heart disease is to rely on something called the Omega-3 Index to determine your individual omega-3 needs rather than using high-dose omega-3 supplements.

  • The Omega-3 Index measures the amount of omega-3 fatty acids in your tissues. It is determined by the amount of omega-3s you consume and how you metabolize them, so it is individualized to you.
  • An Omega-3 Index of 4% is associated with a high risk of heart disease, while an Omega-3 Index of 8% is associated with a low risk of heart disease. There is no evidence that more than 8% provides additional benefit.
  • Most importantly, it only takes 1-1.6 gm/day of omega-3s to raise your Omega-3 Index from 4% to 8%. At these doses your risk of atrial fibrillation and stroke is extremely small.

For example, a recent meta-analysis of 29 studies with a total of 183,292 participants reported that people with an 8% Omega-3 Index had:

  • Decreased risk of ischemic stroke (stroke due to blood clots) with no detectable increased risk of hemorrhagic stroke (stroke due to bleeding), and…
  • No detectable increased risk of atrial fibrillation.

I recommend getting your Omega-3 Index determined, and if it is low, increasing your omega-3 intake to get it into the 8% range. Some people go from 4% to 8% more rapidly than others, so you may need to repeat the test several times to optimize your Omega-3 Index.

If your health professional doesn’t have access to the Omega-3 Index test, you can order it from https://omegaquant.com (I have no financial stake in this company, but I know it as a reputable source of the Omega-3 Index test).

Does The Professor Plan To Reduce His Intake Of Omega-3 Fatty Acids? Three weeks ago, I shared thatprofessor owl my wife and I have been taking around 3 gm/day of omega-3 supplements for the past 40 years. Now that the association of atrial fibrillation and stroke with high dose omega-3 intake has been firmly established, some of you may be wondering whether we plan to decrease our intake of omega-3 supplements.

The answer is, “No”. Remember that the increased risk of atrial fibrillation and stroke is only seen for a small subset of people taking high-dose omega-3 supplements. If we were part of that subset, we would likely have experienced one of those side effects by now.

However, if you are considering omega-3 supplementation for the first time, you don’t know whether you are part of that subset or not. So, my advice remains the same. Rely on optimizing your Omega-3 Index rather than high-dose omega-3 supplementation.

Point #2: Healthy individuals (those with no symptoms of heart disease) do not benefit from omega-3 supplementation. As I pointed out above, this ignores data from their study, namely.

  • Omega-3 supplementation reduced the risk of heart failure in healthy subjects.
  • Omega-3 supplementation reduced the risk of death in higher risk groups within the healthy population (namely men and people 65 and older).

Confusion Clinical StudiesAs I discussed above, this is a pattern seen with statin drugs and most nutritional supplements. Simply put, you can’t show any benefit of statin drugs or most nutritional supplements in a “healthy” population, but you can show benefit when you focus on higher risk individuals within the “healthy” population.

The problem, of course, is that most of us don’t really know whether we are “healthy” or not. For millions of Americans the first indication that they are at risk from heart disease is sudden death from a heart attack or stroke.

With that in mind, I will leave the decision about whether you want to supplement with omega-3s up to you. But if you decide to supplement, I recommend you optimize your Omega-3 Index rather than using a high dose omega-3 supplement.

Point #3: People with heart disease benefit from omega-3 supplementation. This recommendation is becoming non-controversial, so I won’t comment further other than to say high dose omega-3 supplements are probably not needed unless prescribed by your health professional.

The Bottom Line

You have been asking me about recent headlines saying that omega-3 supplements may increase rather than decrease the risk of heart disease. So, I analyzed the study behind the headlines. The study makes 3 claims:

  • Omega-3 supplements increase the risk of atrial fibrillation and stroke when taken by healthy people.
  • Omega-3 supplements are of no benefit for healthy individuals.
  • Omega-3 supplements are beneficial for people who have heart disease.

In the article above I review the flaws, blind spots, and hidden data in the article and discuss what it means for you.

For more details about this study and what it means for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 _______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Is The Mediterranean Diet Healthy For Women?

by

What Does This Study Mean For You? 

Author: Dr. Stephen Chaney 

There is a well-known health disparity in clinical studies related to health. For years most of the studies have been done by men for men. Women have been assumed to experience the same benefits and risks from diet choices as men. But that hasn’t always proven to be true.

The Mediterranean diet is no exception. For example, it has garnered a reputation of reducing heart disease risk for both men and women.

However, most studies on the Mediterranean diet have included primarily male participants or did not report sex specific differences in outcomes.

And the few studies that reported sex specific outcomes have been inconsistent.

  • Some studies have found that men and women benefitted equally from the Mediterranean diet.
  • Other studies have reported that men benefitted more than women.

However, these were all small studies. No meta-analyses have been reported that focused on the heart benefits of the Mediterranean diet for women.

The study (A Pant et al., Heart; 109: 1208-1215, 2023) I will describe today was designed to fill that gap.

How Was The Study Done?

clinical studyThe investigators started by screening the literature to find studies that:

  • Measured adherence to the Mediterranean diet using the original MDS (Mediterranean Diet Score) or more recent modifications of the MDS.
  • Included women ≥18 years without previous diagnosis of clinical or subclinical heart disease.
  • Performed the study with only women participants or organized their data so that the data pertaining to women could be extracted from the study.

The investigators then performed a meta-analysis on data from 722,495 women in 16 studies published between 2006 and 2021 that met these criteria. These studies followed the women for an average of 12.5 years. The studies were primarily conducted in the United States and Europe.

The individual studies divided participants into either quintiles or quartiles and compared participants with the highest adherence to the Mediterranean diet to those with the lowest adherence.

  • The primary outcomes measured were total mortality and the incidence of CVD, cardiovascular disease (defined as including CHD (coronary heart disease), myocardial infarction (heart attack), stroke, heart failure, and cardiovascular death).
  • The secondary outcomes measured were stroke and CHD, coronary heart disease (heart disease caused by atherosclerotic plaque build up in the coronary arteries).

Is The Mediterranean Diet Healthy For Women?

Mediterranean Diet FoodsWhen comparing the highest to the lowest adherence to the Mediterranean diet:

  • The incidence of CVD (cardiovascular disease) was reduced by 24%.
  • Total mortality during the ~12.5-year follow-up was reduced by 23%.
  • The incidence of CHD (coronary heart disease) was reduced by 25%.
  • The risk of stroke was reduced by 13%, but that risk reduction was not statistically significant.
    • The risk reduction for both CVD and total mortality was similar to that previously reported for men.
    • Risk reduction for CVD was slightly higher for women of European descent (24%) than for women of non-European descent (21%). The later category included women of Asian, Native-Hawaiian, and African – American descent.

The authors concluded, “This study supports a beneficial effect of the Mediterranean diet on the primary prevention of CVD and death in women and is an important step in enabling sex-specific guidelines.”

I would add that the data from women of non-European decent suggests that genetic background and/or ethnicity may influence the effectiveness of the Mediterranean diet at reducing heart disease risk, but this effect appears to be small.

What Does This Mean For You?

The results of this study are not unexpected. But that doesn’t mean that studies with women are not valuable. There have been several examples in recent years where health or medical advice based on studies with men needed to be modified for females once the studies were repeated with women.

Before covering what this study means for you, I should point out that while women often fear breast cancer most, heart disease is their number one killer, as the graph on the left shows. In fact, a woman’s risk of dying from coronary heart disease is 6 times greater than her risk of dying from breast cancer.

This study shows that following a Mediterranean–style diet lowers their risk of developing and dying from heart disease. But the Mediterranean diet is not alone in providing these health benefits. It is simply a whole food, primarily plant-based diet that reflects the food preferences of the Mediterranean region.

The DASH diet, which reflects the food preferences of Americans, and the Nordic diet, which reflects the food preferences of the Scandinavian countries, are equally heart healthy. In fact, any whole food, primarily plant-based diet will reduce the risk of heart disease. You should choose the one that best fits your food preferences and lifestyle.

Of course, diet is just part of a holistic approach for reducing heart disease risk. Other important risk reduction strategies include:

  • Don’t smoke.
  • Exercise and maintain a healthy weight.
  • Manage stress.
  • Avoid or limit alcohol.
  • Know your numbers (cholesterol, triglycerides, and blood pressure, for example).
  • Manage other health conditions that increase the risk of heart disease (high blood pressure, diabetes, and high cholesterol, for example).

The Bottom Line

Most studies on the heart health benefits of the Mediterranean diet have been done with men or have not analyzed the data from men and women separately. A recent meta-analysis combining data from 16 studies with 722,495 women showed that the Mediterranean diet was just as heart healthy for women as it was for men.

The authors concluded, “This study supports a beneficial effect of the Mediterranean diet on the primary prevention of CVD and death in women and is an important step in enabling sex-specific guidelines.”

For more details on this study and information on other diets that are heart healthy, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

_____________________________________________________________________________My My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 _____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.

Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Do Omega-3s Improve Recovery From A Heart Attack?

by

Where Do We Go From Here? 

Author: Dr. Stephen Chaney 

Omega-3s And Heart DiseaseDespite years of controversy, the benefits of omega-3s remain an active area of research. Over the next few weeks, I will review several groundbreaking omega-3 studies. This week I will focus on omega-3s and heart health.

I don’t need to tell you that the effect of omega-3s on heart health is controversial. One month a new study is published showing an amazing health benefit from omega-3 supplementation. A month or two later another study comes up empty. It finds no benefit from omega-3 supplementation.

That leads to confusion. On one hand you have websites and blogs claiming that omega-3s are a magic elixir that will cure all your ills. On the other hand, there are the naysayers, including many health professionals, claiming that omega-3 supplements are worthless.

I have discussed the reasons for the conflicting results from omega-3 clinical studies in previous issues of “Health Tips From the Professor”. You can go to https://www.chaneyhealth.com/healthtips/ and put omega-3s in the search box to read some of these articles.

Or if you prefer, I have also put together a digital download I call “The Omega-3 Pendulum” which briefly summarizes all my previous articles. It’s available on my Chaney Health School Teachable website.

Today I will discuss a study (B Bernhard et al, International Journal of Cardiology, 399; 131698, 2024) that asks whether 6 months of high dose omega-3 supplementation following a heart attack reduced the risk of major cardiovascular events over the next 6.6 years.

You might be wondering why the study didn’t just look at the effect of continuous omega-3 supplementation for 6 years following a heart attack. There are two very good reasons for the design of the current study.

1) The investigators wanted to do a double blind, placebo controlled clinical trial, the gold standard for clinical studies. However, that kind of study is impractical for a multi-year clinical trial. It would be prohibitively expensive, and patient compliance would be a big problem for a study that long.

2) The months immediately after a heart attack are critical in determining the long-term recovery of that patient. There is often a period of massive inflammation following a heart attack. And that can lead to further damage to the heart and reclosing of the arteries leading to the heart, both of which increase the risk of future adverse cardiac events.

Previous studies have shown that high dose omega-3s immediately following a heart attack can reduce inflammation and damage to the heart. However, those studies did not determine whether the cardioprotective effect of omega-3 supplementation immediately after a heart attack lead to improved long-term outcomes, something this study was designed to determine.

How Was The Study Done?

clinical studyThe investigators enrolled 358 patients who had suffered a heart attack from three Boston area medical centers between June 2008 and August 2012.

The patient demographics were:

  • Gender = 70% female.
  • Average age = 59
  • Average BMI = 29 (borderline obese).
  • Patients with high blood pressure = 64%
  • Patients with diabetes = 25%.

The patients were divided into two groups. The first group received capsules providing 4 gm/day of EPA, DHA, and other naturally occurring omega-3 fatty acids. The other group received a placebo containing corn oil. This was a double-blind study. Neither the patients nor the investigators knew which patients received the omega-3 fatty acids and which ones received the placebo.

The patients were instructed to take their assigned capsules daily for 6 months. At the beginning of the study, blood samples were withdrawn to determine the percentage of omega-3s in the fatty acid content of their red cell membranes (something called omega-3 index). Patients were also tested for insulin resistance and given a complete cardiovascular workup. This was repeated at the end of the 6-month study.

[Note: Previous studies have shown that an omega-3 index of 4% or lower is associated with high risk of heart disease, and an omega-3 index of 8% or above is associated with a low risk of heart disease.]

At 2-month intervals the patients were contacted by staff using a scripted interview to determine compliance with the protocol and their cardiovascular health. Once the 6 months of omega-3 supplementation was completed, the patients were followed for an additional 6.6 years. They were contacted every 6 months for the first 3 years and yearly between 3 years and 6 years.

The investigators quantified the number of major cardiac events (defined as recurrent heart attacks, the necessity for recurrent coronary artery bypass grafts, hospitalizations for heart failure, and all-cause deaths) for each patient during the 6.6-year follow-up period.

Patients in both groups were treated according to current “standard of care” protocols which consisted of diet and exercise advice and 5-6 drugs to reduce future cardiovascular events.

Do Omega-3s Improve Recovery From A Heart Attack?

heart attacksWhen the investigators looked at the incidence of adverse cardiac events during the 6.6-year follow-up period, there were three significant findings from this study.

1) There were no adverse effects during the 6-month supplementation period with 4 gm/day of omega-3s. This is significant because a previous study with 4 gm/day of high purity EPA had reported some adverse effects which had led some critics to warn that omega-3 supplementation was dangerous. More study is needed, but my hypothesis is that this study did not have side effects because it used a mixture of all naturally occurring omega-3s rather than high purity EPA only. 

However, this could also have been because of the way patients were screened before entering this study. I will discuss this in more detail below.

2) When the investigators simply compared the omega-3 group with the placebo group there was no difference in cardiovascular outcomes between the two groups. This may have been because this study faced significant “headwinds” that made it difficult show any benefit from supplementation. I call them “headwinds” rather than design flaws because they were unavoidable. 

    • It would be unethical to deny the standard of care to any patient who has just had a heart attack. That means that every patient in a study like this will be on multiple drugs that duplicate the beneficial effects of omega-3 fatty acids – including lowering blood pressure, lowering triglycerides, reducing inflammation, and reducing plaque buildup and blood clot formation in the coronary arteries.

That means that this study, and studies like it, cannot determine whether omega-3 fatty acids improve recovery from a heart attack. They can only ask whether omega-3 fatty acids have any additional benefit for patients on multiple drugs that duplicate many of the effects of omega-3 fatty acids. That significantly reduces the risk of a positive outcome.

    • As I mentioned above, it would have been impractical to continue providing omega-3 supplements and placebos during the 6.6-year follow-up.

And the study was blinded, meaning that the investigators did not know which patients got the omega-3s and which patients got the placebo. That meant the investigators could not advise the omega-3 supplement users to continue omega-3 supplementation during the follow-up period.

Consequently, the study could only ask if 6 months of high-dose omega-3 supplementation had a measurable benefit 6.6 years later. I, for one, would be more interested in knowing whether lower dose omega-3 supplementation continued for the duration of this study reduced the risk of major coronary events.good news

3) When the investigators compared patients who achieved a significant increase in their omega-3 index during the 6-month supplementation period with those who didn’t, they found a significant benefit of omega-3 supplementation.

This was perhaps the most significant finding from this study.  

If the investigators had stopped by simply comparing omega-3 users to the placebo, this would have been just another negative study. We would be wondering why it did not show any benefit of omega-3 fatty acid supplementation.

However, these investigators were experts on the omega-3 index. They knew that there was considerable individual variability in the efficiency of omega-3 uptake and incorporation into cell membranes. In short, they knew that not everyone taking a particular dose of omega-3s will achieve the same omega-3 index.

And that is exactly what they saw in this study. All the patients in the 6-month omega-3 group experienced an increase in omega-3 index, but there was considerable variability in how much the omega-3 index increased over 6 months.

So, the investigators divided the omega-3 group into two subgroups – ones whose omega-3 index increased by ≥ 5 percentage points (sufficient to move those patients from high risk of heart disease to low risk) and ones whose omega-3 index increased by less than 5 percentage points.

When the investigators compared patients with ≥ 5% increase in omega-3 index to those with <5% increase in omega-3 index:

  • Those with an increase in omega-3 index of ≥ 5% had a 2.9% annual risk of suffering major adverse cardiac events compared to a 7.1% annual risk for those with an increase of <5%.
  • That’s a risk reduction of almost 60%, and it was highly significant.

The authors concluded, “In a long-term follow-up study, treatment with [high dose] omega-3s for 6 months following a heart attack did not reduce adverse cardiac events compared to placebo. However, those patients who were treated with omega-3s and achieved ≥ 5% rise in omega-3 index experienced a significant reduction of adverse cardiac events after a median follow-up period of 6.6 years…Additional studies are needed to confirm this association and may help identify who may benefit from omega-3 fatty acid treatment following a heart attack.”

What Does This Study Mean For You? 

Questioning WomanI should start by saying that I do not recommend 4 gm/day of omega-3 fatty acids following a heart attack without checking with your doctor first.

  • If you are on a blood thinning medication, the dose of either the medication or the omega-3 supplement may need to be reduced to prevent complications due to excess bleeding.
  • In addition, the investigators excluded patients from this study who might suffer adverse effects from omega-3 supplementation. This is a judgement only your doctor can make.

With that advice out of the way, the most important takeaway from this study is that uptake and utilization of omega-3 fatty acids varies from individual to individual.

The omega-3 index is a measure of how well any individual absorbs and utilizes dietary omega-3s. And this study shows that the omega-3 index is a much better predictor of heart health outcomes than the amount of omega-3 fatty acids a person consumes.

This is not surprising because multiple studies have shown that the omega-3 index correlates with heart health outcomes. It may also explain why many studies based on omega-3 intake only have failed to show a benefit of omega-3 supplementation.

Vitamin D supplementation is a similar story. There is also considerable variability in the uptake of vitamin D and conversion to its active form in the body. 25-hydroxy vitamin D levels in the blood are a marker for active vitamin D. For that reason, I have long recommended that you get your 25-hydroxy vitamin D level tested with your annual physical and, with your doctor’s help, base the dose of the vitamin D supplement you use on that test.

This study suggests that we may also want to request an omega-3 index test and use it to determine the amount of supplemental omega-3s we add to our diet.

Where Do We Go From Here?

Where Do We Go From HereThe idea that we need to use the omega-3 index to determine the effectiveness of the omega-3 supplement we use is novel. As the authors suggest, we need more studies to confirm this effect. There are already many studies showing a correlation of omega-3 index with heart health outcomes. But we need more double blind, placebo-controlled studies like this one.

More importantly, we need to understand what determines the efficiency of supplemental fatty acid utilization so we can predict and possibly improve omega-3 utilization. The authors suggested that certain genetic variants might affect the efficiency of omega-3 utilization. But the variability of omega-3 utilization could also be affected by:

  • Diet, especially the presence of other fats in the diet.
  • Metabolic differences due to obesity and diseases like diabetes.
  • Gender, ethnicity, and age.
  • Design of the omega-3 supplement.

We need much more research in these areas, so we can personalize and optimize omega-3 supplementation on an individual basis.

The Bottom Line 

A recent study asked whether high dose omega-3 supplementation for 6 months following a heart attack reduced major cardiac events during the next 6.6 years.

  • When they simply compared omega-3 supplementation with the placebo there was no effect of omega-3 supplementation on cardiac outcomes.
  • However, when they based their comparison on the omega-3 index (a measure of how efficiently the omega-3s were absorbed and incorporated into cell membranes), the group with the highest omega-3 index experienced a 60% reduction in adverse cardiac events over the next 6.6 years.

This is consistent with multiple studies showing that the omega-3 index correlates with heart health outcomes.

More importantly, this study shows there is significant individual variation in the efficiency of omega-3 absorption and utilization. It also suggests that recommendations for omega-3 supplementation should be based on the omega-3 index achieved rather than the dose or form of the omega-3 supplement.

For more information on this study and what it means for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are Calcium Supplements Heart Healthy?

by

Should You Follow Your Doctor’s Advice About Calcium Supplementation?

Author: Dr. Stephen Chaney

Heart ConfusionAre calcium supplements good for your heart or bad for your heart? If you don’t know the answer to that question, don’t feel badly. You have every right to be confused. Some studies say that calcium supplements increase heart disease risk while others say they decrease heart disease risk. The headlines have veered between “killer calcium” and “beneficial calcium”.

The trend appears to be moving in a positive direction. In recent years most of the studies have suggested that calcium supplements either decrease heart disease risk or have no effect on heart disease risk.

However, the medical profession has been slow to take note of this trend. Most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements. I will talk more about that recommendation below.

With this context in mind, this week I will review and discuss the results from the latest study (MG Sim et al, Heart, Lung and Circulation, 32: 1230-1239, 2023) on the effect of calcium supplementation on heart disease risk.

How Was This Study Done?

Clinical StudyThe authors of this study performed a meta-analysis of 12 double-blinded randomized clinical trials with 87,899 participants comparing the effect of a calcium supplement versus a placebo on heart disease outcomes (heart attack, stroke, heart failure, cardiovascular mortality, and all-cause mortality).

The studies included in this analysis:

  • Used calcium doses from 500 mg/day to 2,000 mg/day.
  • Used supplements with calcium coming from a variety of sources (calcium carbonate, calcium citrate, calcium gluconolactate, and tricalcium phosphate).
  • Ranged from 18 months to almost 12 years in length.
  • Were performed with population groups from a wide range of countries (United States, England, France, Australia, New Zealand, European Union, Denmark, and Thailand).
  • Included calcium supplements with and without vitamin D.
  • Were primarily (86% of participants) conducted with post-menopausal women. One small study (0.3% of participants) was conducted with non-osteoporotic men. The rest were conducted with mixed populations (men and women) diagnosed with colorectal adenoma.

Are Calcium Supplements Heart Healthy?

calcium supplementsThis is the largest meta-analysis performed to date of double-blind, placebo-controlled randomized clinical trials on the effect of calcium supplementation versus a placebo on heart disease outcomes. This study found no effect of calcium supplementation on:

  • Heart attack.
  • Stroke
  • Heart failure.
  • Cardiovascular mortality.
  • All-cause mortality.

This study also evaluated potential confounding variables and found no effect of calcium supplementation on heart disease risk for:

  • Calcium supplements with and without vitamin D.
  • Dosage of calcium in the supplements (The dosage ranged from 500 mg/day to 2,000 mg/day).
  • Females (I suspect the number of males in this study was too small to come to a statistically significant conclusion).
  • Duration of calcium supplementation ≤ 5 years (The shortest duration of calcium supplementation in these studies was 18 months).
  • Different geographical regions.

However, this meta-analysis reported considerable variation between studies included in the analysis. Simply put,

  • Some studies showed an increase in heart disease risk.
  • Some studies showed a decrease in heart disease risk.
  • Some studies showed no effect on heart disease risk.

What this analysis showed was that when you combine all the studies, the aggregated data is consistent with calcium supplementation having no effect on heart disease risk.

The authors concluded, “Calcium supplementation was not associated with myocardial infraction [heart attack], stroke, heart failure, and cardiovascular/all-cause mortality. Further studies are required to examine and understand these associations.

Should You Follow Your Doctor’s Advice About Calcium Supplementation?

Doctor With PatientAs I said above, most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements. That may be the advice you are getting from your doctor.

Before you assume your doctor isn’t keeping up with the latest science and ignore his or her advice, we should ask why they are giving that advice. The top three reasons most medical societies give for recommending dietary sources of calcium are:

1) Some studies do show an increased risk of heart disease associated with calcium supplementation. The prime directive for health professionals is to do no harm. Yes, the average of all studies shows no effect of calcium supplementation on heart disease risk. But what if the studies showing increased risk are true for some of their patients? Those patients could be harmed. 

Are you someone who might be at increased risk for heart disease if you take calcium supplements. The short answer is we don’t know because previous studies have not asked the right questions. 

In my opinion, it is time to pause additional studies and meta-analyses on calcium supplementation and heart health until we have gone over existing studies with a fine-tooth comb to figure out why the results differ so wildly. For example, we need to ask whether the effect of calcium supplements on heart disease risk is influenced by things like:

    • Age or ethnicity of participants.
    • Other preexisting health conditions.
    • Other lifestyle factors (exercise is probably the most important, but others may be involved as well).
    • Diet context. For example, we already know that the effect of eggs and dairy on heart health is influenced by diet context. [I have covered this for eggs in a previous issue of “Health Tips From the Professor”.]
    • Other unanticipated variables.

Only when we have identified variables that might influence the effect of calcium supplements on heart disease risk, will the scientific community be able to design studies to identify the population groups who might be adversely affected by calcium supplementation.

This would allow health professionals to make informed decisions about which of their patients should avoid calcium supplementation and which of their patients would benefit from calcium supplementation. 

2) We really don’t need the recommended RDAs for calcium to build strong bones. The Healthy Bonerecommended RDAs for calcium are 1,000 mg/day for adults 19-50, 1,000 mg/day for men and 1,200 mg/day for women 51-70, and 1,200 mg/day for both men and women over 70. But do we really need that amount of calcium to build healthy bones? 

I have discussed this topic in detail in a previous issue of “Health Tips From the Professor”. Here are the key points:

    • The current RDAs are based on calcium needs for people consuming the typical American diet and following the typical American lifestyle. If that is you, the current RDAs probably apply.
    • However, strong bones are absolutely dependent on three things, adequate calcium, adequate vitamin D, and adequate weight-bearing exercise. Most recent studies of calcium supplementation and bone density include adequate vitamin D, but almost none of them include exercise. Previous studies have been inadequate.
    • The best calcium supplements contain certain nutrients besides vitamin D that optimize bone formation. I have listed those nutrients in the article cited above.
    • Our ability to use calcium to build strong bones is dependent on diet (something I call a bone-healthy diet) and lifestyle (something I call a bone-healthy lifestyle).
    • For more information on each of these points, read the article I referenced above.

In short, I agree that the current calcium RDAs may be too high for individuals consuming a bone-healthy diet and following a bone-healthy lifestyle. But the current calcium RDAs are likely accurate for people consuming the typical American diet and following the typical American lifestyle.

    • While we do not have a calcium RDA for populations following a bone healthy diet lifestyle, some studies suggest that 700-800 mg of calcium/day may be sufficient for this group.

3) Calcium from supplements is absorbed faster and gives higher blood level spikes than calcium from foods. That could be a problem because high blood levels of calcium are associated with calcification of our arteries, which is associated with increased heart disease risk. 

This is a theoretical concern, because high blood calcium levels from supplementation are transitory, while it is continuous high blood calcium levels that are associated with calcification of our arteries.

However, it is a plausible concern because most supplement companies design their calcium supplements based on how quickly they get calcium into the bloodstream rather than how effectively the calcium is utilized for bone formation. Here are my recommendations:

    • Choose a calcium supplement that provides RDA levels of vitamin D plus other nutrients shown to support strong bone formation.
    • Choose a calcium supplement supported by clinical studies showing it is effectively utilized for bone formation.

4) We should be getting our calcium from foods rather than supplements. dairy foods

While it is always easy for doctors to recommend that we get our nutrients from food rather than supplements, they need to ask whether we are getting those nutrients from our diet. For calcium the data are particularly sobering.

    • The average American gets around 740 mg of calcium/day from their diet. That is probably enough for the small percentage of Americans following a bone healthy diet and lifestyle. But it is 260-460 mg short of the 1,000-1,200 mg/day recommended for older adults with the typical American diet and lifestyle.
      • And for the average American, around 70% of their calcium intake comes from dairy foods.

       

      • So, Americans who are following a typical American diet and lifestyle and are restricting dairy may require 800-1,000 mg/day of supplemental calcium unless they carefully plan their diets to optimize calcium intake.

       

      • Finally, vegans average about 550 mg/day from their diet. That might be borderline even if they were following a bone healthy lifestyle.
    • In short, we cannot assume our diet will provide enough calcium for strong bones unless we include dairy foods and/or plan our diet very carefully. Some degree of supplementation may be necessary.

How Much Calcium Do You Need?

Questioning Woman

I have covered a lot of territory in this article, so let me summarize the four concerns of the medical community and answer your most important question, “Should you take calcium supplements?”

1) Calcium supplements may increase the risk of heart disease for some people.

That is true, but we have no idea at present who is at increased risk and who isn’t. So, we should minimize our risk by taking the precautions I describe below.

2) We don’t need RDA levels of calcium to build strong bones. That is probably true if you are one of the few people who follows a bone healthy diet and lifestyle, but it isn’t true if you follow the typical American diet and lifestyle.

  • The current RDAs of 1,000 – 1,200 mg/day are a good guideline for how much calcium you need if you follow the typical American diet and lifestyle.
  • If you a one of the few people who follow a bone healthy diet and lifestyle (For what that involves, read this article) you may only need 700-800 mg/day. But we don’t have clinical studies that can tell us what the actual RDA for calcium should be under those circumstances.

3) Calcium from supplements is absorbed faster and gives higher blood calcium spikes than calcium from foods. You may remember that the theoretical concern is that even short-term spikes of high blood calcium may lead to calcification of your arteries, which increases your risk of heart disease. So, the important question becomes, “What can we do to minimize these spikes in blood calcium levels?”

  • We should avoid calcium supplements that brag about how quickly and efficiently the calcium is absorbed. That could lead to calcium spikes. Instead, we should look for calcium supplements that are backed by clinical studies showing they are efficiently utilized for bone formation.
  • We should look for calcium supplements that include RDA levels of vitamin D and other nutrients that optimize bone formation. You will find more information on that in the same article I referenced above.
  • Some experts recommend that calcium supplements be taken between meals. But it is probably better to take them with meals because foods will likely slow the rate at which calcium is absorbed and reduce calcium spikes in the blood.
  • We are told to limit calcium supplements to less than 500 mg at any one time because calcium absorption becomes inefficient at higher doses. It might be even better to limit calcium to 250 mg or less at a time to reduce calcium spikes in the blood.

4) We should get calcium from foods rather than supplements.

  • Many Americans do not get enough calcium from diet alone, especially if they avoid dairy foods. So, some degree of calcium supplementation may be necessary. I have given some guidelines depending on your diet and lifestyle above.
  • The amount of supplemental calcium needed is relatively small. I do not recommend exceeding the RDA unless directed to by your health professional.

The Bottom Line 

Some studies say that calcium supplements increase heart disease risk while others say they decrease heart disease risk. The headlines veer between “killer calcium” and “beneficial calcium”.

The trend appears to be moving in a positive direction. In recent years most of the studies have suggested that calcium supplements either decrease heart disease risk or have no effect on heart disease risk.

However, the medical profession has been slow to take note of this trend. Most medical societies and health professionals have focused on earlier studies and are still recommending that their patients get calcium from food rather than from supplements.

A recent meta-analysis of 12 double-blinded randomized clinical trials with 87,899 participants comparing the effect of a calcium supplement versus a placebo on heart disease outcomes has just been published. This study found no effect of calcium supplementation on:

  • Heart attack.
  • Stroke.
  • Heart failure.
  • Cardiovascular mortality.
  • All-cause mortality.

The authors of the study concluded, “Calcium supplementation was not associated with myocardial infraction [heart attack], stroke, heart failure, and cardiovascular/all-cause mortality.

For more details and advice on whether you should follow your doctor’s recommendations for calcium supplementation read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 _____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

____________________________________________________________________

About The Author

Dr. Steve ChaneyDr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

 

Which Diets Are Heart Healthy?

by

Which Diet Is Best For You?

Author: Dr. Stephen Chaney 

strong heartThe top 3 claims the advocates of every popular diet make are:

  • It will help you lose weight.
  • It reduces your risk of diabetes.
  • It reduces your risk of heart disease.

The truth is any restrictive diet helps you lose weight. And when you lose weight, you improve blood sugar control. Which, of course, reduces your risk of developing diabetes.

But what about heart disease? Which diets are heart healthy? When it comes to heart disease the claims of diet advocates are often misleading. That’s because the studies these advocates use to support their claims are often poor quality studies. Many of these studies:

  • Look at markers of heart disease risk rather than heart disease outcomes. Markers like LDL cholesterol, triglycerides, c-reactive protein, etc. are only able to predict possible heart disease outcomes. To really know which diets are heart healthy you have to measure actual heart disease outcomes such as heart attacks, stroke, and cardiovascular deaths.
  • Are too short to provide meaningful results. Many of these studies last only a few weeks. You need much longer to measure heart disease outcomes.
  • Are too small to provide statistically significant results. You need thousands of subjects to be sure the results you are seeing are statistically significant.
  • Have not been confirmed by other studies. The Dr. Strangeloves of the world like to “cherry pick” the studies that support the effectiveness of their favorite diet. Objective scientists know that any individual study can be wrong. So, they look for consensus conclusions from multiple studies.

A recent study (G Karam et al, British Medical Journal, 380: e072003, 2023) avoided all those pitfalls. The investigators conducted a meta-analysis of 40 high-quality clinical studies with 35,548 participants to answer the question, “Which diets are heart healthy?”

How Was The Study Done?

Clinical StudyThe authors started by searching all major databases of clinical studies for studies published on the effect of diets on heart disease outcomes through September 2021.

They then performed a meta-analysis of the data from all studies that:

  • Compared the effect of a particular diet to minimal dietary intervention (defined as not receiving any advice or receiving dietary information such as brochures or brief advice from their clinician with little or no follow-up).
  • Looked at heart disease outcomes such as all cause mortality, cardiovascular mortality, non-fatal heart attacks, stroke, and others.
  • Lasted for at least 9 months (average duration = 3 years).
  • Were high-quality studies.

Using these criteria:

  • They identified 40 studies with 35,548 participants for inclusion in their meta-analysis.
    • From those 40 studies, they identified 7 diet types that met their inclusion criteria (low fat (18 studies), Mediterranean (12 studies), very low fat (6 studies), modified fat (substituting healthy fats for unhealthy fats rather than decreasing fats, 4 studies), combined low fat and low sodium (3 studies), Ornish (3 studies), Pritikin (1 study).

One weakness of meta-analyses is that the design of the studies included in the meta-analysis is often different. Sometimes they don’t fit together well. So, while the individual studies are high-quality, a combination of all the studies can lead to a conclusion that is low quality or moderate quality.

Finally, the data were corrected for confounding factors such as obesity, exercise, smoking, and medication use.

Which Diets Are Heart Healthy?

Now that you understand the study design, we are ready to answer the question, “Which diets are heart healthy?” Here is what this study found:

Compared to minimal intervention,

  • The Mediterranean diet decreased all cause mortality by 28%, cardiovascular mortality by 45%, stroke by 35%, and non-fatal heart attacks by 52%.
  • Low fat diets decreased all cause mortality by 16% and non-fatal heart attacks by 23%. The effect of low fat diets on cardiovascular mortality and stroke was not statistically significant in this meta-analysis.
    • For both the Mediterranean and low fat diets, the heart health benefits were significantly better for patients who were at high risk of heart disease upon entry into the study.
    • The evidence supporting the heart health benefits for both diets was considered moderate quality evidence for this meta-analysis. [Remember that the quality of any conclusion in a meta-analysis is based on both the quality of evidence of the individual studies plus how well the studies fit together in the meta-analysis.]
  • While the percentage of risk reduction appears to be different for the Mediterranean and low fat diets, the effect of the two diets on heart health was not considered significantly different in this study.
  • The other 5 diets provided little, or no benefit, compared to the minimal intervention control based on low to moderate quality evidence.

The authors concluded, “This network meta-analysis found that Mediterranean and low fat dietary programs probably reduce the risk of mortality and non-fatal myocardial infarction [heart attacks] in people at increased cardiovascular risk. Mediterranean dietary programs are also likely to reduce the risk of stroke. Generally, other dietary programs were not superior to minimal intervention.”

Which Diet Is Best For You?

confusionThe fact that this study found both the Mediterranean diet and low fat diets to be heart healthy is not surprising. Numerous individual studies have found these diets to be heart healthy. So, it is not surprising when the individual studies were combined in a meta-analysis, the meta-analysis also concluded they were heart healthy. However, there are two important points I would like to make.

  • The diets used in these studies were designed by trained dietitians. That means the low fat studies did not use Big Food, Inc’s version of the low fat diet in which fatty foods are replaced with highly processed foods. In these studies, fatty foods were most likely replaced with whole or minimally processed foods from all 5 food groups.
  • The Mediterranean diet is probably the most studied of current popular diets. From these studies we know the Mediterranean diet improves brain health, gut health, and reduces cancer risk.

As for the other 5 diets (very low fat, modified fat, low fat and low sodium, Ornish, and Pritikin), I would say the jury is out. There is some evidence that these diets may be heart healthy. But very few of these studies were good enough to be included in this meta-analysis. Clearly, more high-quality studies are needed.

Finally, you might be wondering why other popular diets such as paleo, low carb, and very low carb (Atkins, keto, and others) were left out of this analysis. All I can say is that it wasn’t by design.

The authors did not select the 7 diets described in this study and then search for studies testing their effectiveness. They searched for all studies describing the effect of diets on heart health. Once they identified 40 high-quality studies, they grouped the diets into 7 diet categories.

I can only conclude there were no high-quality studies of paleo, low carb, or very low carb diets that met the criteria for inclusion in this meta-analysis. The criteria were:

  • The effect of diet on heart health must be compared to a control group that received no or minimal dietary advice.
  • The study must measure heart disease outcomes such as all cause mortality, cardiovascular mortality, non-fatal heart attacks, and stroke.
  • The study must last at least 9 months.
  • The study must be high-quality.

Until these kinds of studies are done, we have no idea whether these diets are heart healthy or not.

So, what’s the takeaway for you? Which diet is best for you? Both low fat diets and the Mediterranean diet are heart healthy provided the low fat diet consists of primarily whole or minimally processed foods. Which of these two diets is best for you depends on your food preferences.

The Bottom Line 

Many of you may have been warned by your doctor that your heart health is not what it should be. Others may be concerned because you have a family history of heart disease. You want to know which diets are heart healthy.

Fortunately, a recent study answered that question. The authors performed a meta-analysis of 40 high-quality studies that compared the effect of various diets with the effect of minimal dietary intervention (doctors’ advice or diet brochure) on heart disease outcomes.

From this study they concluded that both low fat diets and the Mediterranean diet probably reduce mortality and the risk of non-fatal heart attacks, and that the Mediterranean diet likely reduces stroke risk.

Other diets studied had no significant effect on heart health in this study. That does not necessarily mean they are ineffective. But it does mean that more high-quality studies are needed before we can evaluate their effect on heart health.

So, what’s the bottom line for you? Both low fat diets and the Mediterranean diet are heart healthy provided the low fat diet consists of primarily whole or minimally processed foods Which of these two diets is best for you depends on your food preferences.

For more information on this study, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Does Hormone Replacement Therapy Cause Dementia?

by

The Dark Side Of Hormone Replacement Therapy

Author: Dr. Stephen Chaney 

When I was still teaching, a physician and I were co-directors of one of the first courses medical students took at UNC. In his opening lecture to these brand-new medical students, one of his pearls of wisdom was the statement, “The only safe drug is a new drug.”

After a pause to let the students think about it, he followed up with, “That’s because the side effects haven’t been discovered yet.”

He would then go on to explain that every drug must go through rigorous clinical trials, and some side effects are discovered then. But some of the most serious side effects aren’t discovered until years later after 100’s of thousands of patients had used the drugs.

Hormone replacement therapy is a perfect example of this principle. Hormone replacement therapy was first introduced in the 1960s. At first it seemed to be an almost miraculous solution to menopausal symptoms.

Millions of women were overjoyed. After all, menopause symptoms can make life miserable. They include:

  • Hot flashes
  • Night sweats
  • Sleep disturbances
  • Mood swings
  • Depression
  • Anxiety
  • Forgetfulness
  • Food cravings
  • Tiredness

Just to name a few. While only 25% of women experience severe symptoms, why would anyone want to experience any of these symptoms?

And doctors were only too happy to oblige. Why not? The known side effects were mild. Why should any woman experience menopause symptoms?

But that was before the dark side of hormone replacement therapy started to emerge.

The Dark Side Of Hormone Replacement Therapy

Darth VaderThe popularity of hormone replacement therapy peaked in the 1990s. It was around that time that reports started to emerge suggesting that hormone replacement therapy increased the risk of heart disease and breast cancer. Those risks were confirmed in a major study called the Woman’s Health Initiative that was published in 2002.

That study caused a major shift in how the medical community regarded hormone replacement therapy. Within a few years doctors shifted from recommending hormone replacement therapy for every woman with menopausal symptoms to recommending it only in cases where the symptoms were debilitating and only for the shortest possible time.

The effect on women’s health was huge. In fact, switching from universal hormone replacement therapy to targeted hormone replacement therapy remains the single most effective public health measure for reducing the incidence of breast cancer. It is more effective than any of new drugs and measures to improve breast cancer screening since then.

I wish I could tell you that was the end of the story. But recent studies have suggested that hormone replacement therapy also increases the risk of dementia. Unfortunately, most of those studies have had flaws, so the link between hormone replacement therapy and dementia has remained controversial – until now.

The study (N Pourhadi et al, British Medical Journal, 382, e072770, 2023) I will describe today was designed to provide a more definitive test of this hypothesis.

How Was This Study Done?

clinical studyThis was done in Denmark and used the Danish health registries. As Americans, you might not be aware of what a rich resource those health registries are. One advantage of socialized medicine is that every aspect of your health is tracked and recorded from cradle to grave.

[I’m not sure I would be comfortable with our government knowing that much about me, but it is a treasure-trove of information if you want to conduct a study like this one.]

The authors used the Danish National Health registries to:

  • Identify all Danish women aged 50-60 who had no incidence of dementia and were not on hormone replacement therapy as of January 1, 2000.
  • Identify 5589 women (1.8% of the population) from this group who were diagnosed with dementia between January 1, 2000 and December 31, 2018 and match them with 55,890 controls who remained dementia-free through the end of 2018.
  • Using the National Prescription registry, they were able to track which women used hormone-replacement therapy, what kind of therapy it was (there are several variations of hormone replacement therapy), and how long they remained on hormone replacement therapy.

The average age at which hormone replacement therapy began was 53, and the average duration of use was 3.8 years. The average age of a dementia diagnosis was 70.

Does Hormone Replacement Therapy Cause Dementia?

Dementia-WomanWhen the authors compared women who used an estrogen-progestin combination hormone replacement therapy (the most common kind) with women who never used hormone replacement therapy, the hormone replacement therapy users were:

  • 24% more likely to develop dementia of any kind.
  • 21% more likely to develop late-onset dementia.
  • 22% more likely to develop Alzheimer’s disease.

Longer duration of hormone replacement use was associated with an increased risk of dementia. The increased risk of dementia was:

  • 21% for ≤ 1 year duration.
  • 39% for 8-12 years duration.
  • 74% for > 12 years duration.

The age at which hormone replacement therapy was begun had a slight effect on dementia risk. The increased risk of dementia was:

  • 26% when it was started at age 45-50.
  • 21% when it was started at age 51-60.

Finally, other forms of hormone replacement therapy such as progestin only therapy and vaginal estrogen treatment did not have a statistically significant effect on dementia risk. But it was not clear whether this was due to a smaller sample size or whether it was a true null effect.

The authors concluded, “Menopausal hormone replacement therapy was positively associated with the development of all cause dementia and Alzheimer’s disease, even in women who received treatment at the age of 55 years or younger.”

The Pros And Cons Of This Study

pros and consThe pros are obvious. This was a large, well-designed study. And its use of the Danish National Health registry and National Prescription registry allowed it to address the dementia risk of hormone replacement therapy in a comprehensive manner.

The cons are also obvious. This was an observational study. It can only show associations, not prove cause and effect. [I should note that it would be impossible to do a double-blind study to prove cause and effect. The size of the population group and the length of time required would make that kind of study unworkable.]

As I have said in previous issues of “Health Tips From the Professor”, the Achilles heel of observational studies is the possibility that a confounding variable (something else about the women who developed dementia) was the true cause of the observed outcome (in this case, increased dementia risk).

The authors did an excellent job of identifying known confounding variables that might have contributed to dementia and statistically correcting for them. However, the authors identified one potential confounding variable I would not have thought of.

In the words of the authors, “Further studies are warranted to determine whether these findings represent an actual effect of menopausal hormone therapy on dementia risk, or whether they reflect an underlying predisposition in women in need of these treatments.”

In case you need a translation, the authors are saying that it is possible that certain women have an underlying disease state or genetic predisposition that makes them very sensitive to menopausal symptoms (which increases the likelihood that they would receive hormone replacement therapy to reduce their symptoms) and increases their risk of dementia. In that case, it would be the underlying medical condition or genetic predisposition that was responsible for the increased dementia risk, not the hormone replacement therapy.”

I consider that unlikely, but it does warrant future studies.

Is Hormone Replacement Therapy Right For You?

Questioning WomanUltimately, this is your decision. But this is a decision you should make with your health care provider.

It is clear that hormone replacement therapy increases your risk of heart disease, breast cancer, and may increase your risk of dementia.

In part, your decision depends on the severity of your symptoms and your willingness to accept the risks associated with alleviating those symptoms.

But your health care provider can also help you consider family history and unrelated health conditions that may also increase your risk of these diseases. If your underlying disease risk is low, would you be more willing or less willing to accept the risks associated with hormone replacement therapy? Again, this is your decision.

And, if you decide to proceed with hormone replacement therapy, your health care provider can recommend the type of therapy and length of therapy that will minimize your risks.

The Bottom Line 

Several recent studies have suggested that hormone replacement therapy may increase the risk of dementia, but this has remained controversial.

In this issue of “Health Tips From the Professor” I share a very large, well designed study that supports the link between hormone replacement therapy and dementia.

When the authors of this study compared women who had used hormone replacement therapy with women who never used hormone replacement therapy, the hormone replacement therapy users were:

  • 24% more likely to develop dementia of any kind.
  • 21% more likely to develop late-onset dementia.
  • 22% more likely to develop Alzheimer’s disease.

The authors concluded, “Menopausal hormone replacement therapy was positively associated with the development of all cause dementia and Alzheimer’s disease, even in women who received treatment at the age of 55 years or younger.”

For more information on the strengths and weaknesses of this study and a discussion of whether hormone replacement therapy might be right for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 

Health Tips From The Professor